Hyperreflective points and cytokines as clinical and molecular markers in retinal detachment

Abstract

Purpose : Retinal detachment (RD) is one of the most frequently diagnosed ophthalmologic conditions requiring prompt surgical intervention. Combination of proper surgical technique and new diagnostic markers, both clinical and molecular, can help improve the diagnosis and prognosis of RD.

Methods : 10 rhegmatogenous RD patients were included in the study after obtaining patient consent and Regional Ethical Approval (average age: 64.1 ± 13.7). OCT was performed in all RDs before surgery and a day after 23G vitrectomy. Subretinal fluid (SRF) was collected during surgery and analyzed by ELISA for presence of inflammatory factors (IL-6, IL-8), while the effect of SRF upon human macrophages-led phagocytosis of apoptotic retinal pigment epithelial (RPE) cells was studied ex vivo and quantified by flow cytometry. Immunohistochemistry (IHC) of an eye enucleated due to phthisis bulbi following several RD surgeries due to PVR was performed to determine presence of markers for microglial cells (CD34) and macrophages (CD14, CD68).

Results : OCT of fresh RD patients contained hyperreflective points (HRPs) at the detached neuroretina border and proximal to the RPE layer - their size and number decreased following successful reattachment surgery. IHC of the phthitic eye showed presence of cell conglomerates at the detached neuroretina border which were positive for CD68 and negative for CD34 and CD14. The SRF had higher concentration of IL-6 and IL-8 compared to vitreous from non-RD pathology; when given to macrophages, the SRF doubled their capacity for engulfing dying RPE cells ex vivo.

Conclusions : Fresh RD can be hallmarked by a presence of HRPs at the detached neuroretina border on OCT; the HRPs disappear after successful reattachment surgery, and likely resemble the macrophage conglomerates seen by IHC. The SRF contains pro-inflammatory factors which increase the ability of professional phagocytes to engulf dying RPE, or for that matter, other dying cells in the retina.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.